Note 8 - Leases (Details Textual) $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jul. 31, 2019
Operating Lease, Right-of-Use Asset	$ 24,840	$ 25,715
Operating Lease, Weighted Average Discount Rate, Percent	9.80%
Operating Lease, Weighted Average Remaining Lease Term (Year)	5 years 1 month 13 days
Right of Use for Office and Manufacturing Facilities with Initial Terms Exceeding One Year [Member]
Lessee, Operating Lease, Number of Right-of-Use Leases	6
South San Francisco Real Estate [Member]
Lessee, Operating Lease, Renewal Term (Year)	8 years			5 years
September 2021 Lease for Facility in South San Francisco [Member]
Lessee, Operating Lease, Renewal Term (Year)	8 years
Lease for Facility in South San Francisco Commenced in First Quarter of 2023 [Member]
Operating Lease, Right-of-Use Asset			$ 3,100
Facility in South San Francisco [Member]
Lessee, Operating Lease, Renewal Term (Year)	5 years
Facility in Burlingame, California [Member]
Lessee, Operating Lease, Renewal Term (Year)	30 months
Operating Lease, Right-of-Use Asset	$ 3,100	$ 15,000
Lessee, Short-term Lease, Number of Leases	2
Lessee, Operating Lease, Number of Renewal Option	2